Transparent substrate and method of manufacturing the same

ABSTRACT

At least one monomolecule film is formed on a transparent substrate surface directly or via a protective film. The monomolecule film is formed with chemical coupling of chlorosilane surface active compound, for example, of the formula: 
     F(CF 2 )m(CH 2 )nSiR q X 3 — q   
     where m is an integer of from 1 to 15, n is an integer of from 0 to 15 provided that the total of m and n is an integer of from 10 to 30 and R is an alkyl or an alkoxyl group, or 
     F(CF 2 )m′(CH 2 )n′A(CH 2 )pSiR q X 3−q   
     where m represents an integer ranging from 1 to 8, n′ represents an integer ranging from 0 to 2, p represents an integer ranging from 5 to 25, q represents an integer ranging from 0 to 2, X represents a halogen atom or an alkoxyl group, R represents an alkyl or an alkoxyl group, and A represents —O—, a —COO— or —Si(CH 3 ) 2 —. The transparent substrate such as glass is made hydrophobic and free of contamination.

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. Nos. 08/279,686, filed Jul. 25, 1994, and of 08/383,428, filed Feb.03, 1995, each of which claim parentage to original parent applicationSer. No. 07/798,525, filed Nov. 26, 1991, which in turn claims thepriority of Japanese Patent Applications 2-407555 and 3-038135 filed onDec. 25, 1990 and Feb. 06, 1991, respectively.

FIELD OF THE INVENTION

[0002] This invention relates to a transparent substrate. Moreparticularly, the present invention relates to a hydrophobic, oil-phobicand/or contamination-free transparent substrate such as motor vehicleand building window glasses, windshields, optical lenses and glasslenses etc.

BACKGROUND OF THE INVENTION

[0003] In order to prevent contamination of a transparent substrate suchas glass, it has been proposed to make the surface of the transparentsubstrate as smooth as possible or coat the substrate surface with aprotective film such as a fluorine-based coating film or the like.Further, to prevent fogging of the transparent substrate surface, ahydrophilic polymer is coated thereon, or a heater is installed in oronto the transparent substrate.

[0004] Where the contamination of a transparent substrate stems fromwater drops, an antifogging effect can be obtained by installing aheater. However, the use of a heater has a drawback, namely a powersource for the heater is necessary. Furthermore, a heater which isburied in or installed on the surface of the transparent substrate mayreduce the transparency thereof. Coating the transparent substratesurface with a hydrophilic polymer or the like is comparatively simple.However, only a tentative effect is achieved because the hydrophilicpolymer may be peeled off by rubbing the transparent substrate surface.

[0005] Where contamination of the substrate surface stems from othercauses the above methods are substantially meaningless. Accordingly, ithas been proposed to coat the transparent substrate surface with aprotective film, for example fluorine-based coatings. However, theadhesion between the transparent substrate and a fluorine-basedprotective film is weak. Therefore the film is readily separated fromthe substrate surface. In addition, the fluorine-based protective filmcauses fogging of the transparent substrate due to its opaqueness. Otherprotective film materials can improve upon the transparency and adhesionof the flourine-based protective films. However, these materials do notenable easily wiping-out of contaminants. Accordingly, it is a practicalmethod to make the surface of the transparent substrate as smooth aspossible. However, there are limitations on the degree of smoothness ofthe substrate surface which one skilled in the art can attain. Thus,there is a need for a contamination free, hydrophobic and/or oil phobictreated transparent substrate.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a highlyhydrophobic and contamination free transparent substrate, which is freefrom the attachment of contaminants thereon or is capable of the readyremoval of any attached contaminants.

[0007] To attain this object, the instant invention provides atransparent substrate, which is provided on at least one surface thereonwith a chemically adsorbed monomolecule film containing a hydrophobicgroup.

[0008] A first aspect of this invention provides a transparent substratecomprising at least one monomolecule film formed as an outer mostsurface layer on at least one surface of a transparent substrate eitherdirectly or indirectly via a protective film. The monomolecule filmcontains a hydrophobic group and is bonded through covalent bonding tothe surface of the substrate or of the protective film. Preferably, theprotective film is itself one or more of such monomolecule filmscontaining a hydrophobic group and bonded through a covalent bond to thesurface of the substrate. A difference between the (a) monomolecule filmof the protective film and (b) the outer most surface layer monomoleculefilm is that (a) is at or near the end of the hydrophobic group and theprotective film monomolecule is bonded through a covalent bond to (b),the outer most surface layer monomolecule film. Another difference isthat (b) is bonded to the protective layer monomolecule film one layercloser to the outer most surface. One preferred embodiment of the firstaspect of this invention provides a transparent substrate comprising amonomolecule film formed as an outer surface layer on both surfaces of atransparent substrate either directly or indirectly via a protectivefilm. In particular, one of the surfaces (the first surface) is coveredwith a monomolecule film containing a hydrophobic group which iscovalently bonded to the first surface. The other surface (the secondsurface) is covered with a monomolecule film containing a hydrophilicgroup which is covalently bonded to the second surface.

[0009] According to another embodiment of the first aspect of thisinvention, the monomolecule film is formed by a covalent bond from asilane halide-based or alkoxy silane-based surface-active compound ofthe formula:

F(CF₂)_(m)(CH₂)_(n)SiR_(q)X_(3−q)  (A)

[0010] where m represents an integer ranging from 1 to 15, n representsan integer ranging from 0 to 15, the sum of m and n ranges from 10 to30, q represents an integer ranging from 0 to 2, R represents an alkylor an alkoxyl group. and X is a halogen atom or an alkoxyl group; or

F(CF₂)_(m′)(CH₂)_(n′)A(CH₂)_(p)Si R_(q)X_(3−q)  (B)

[0011] where m′ represents an integer ranging from 1 to 8, n′ representsan integer ranging from 0 to 2 p represents an integer ranging from 5 to25, q represents an integer ranging from 0 to 2, X represents a halogenatom or an alkoxyl group, R represents an alkyl or an alkoxyl group, andA represents —O—, a —COO— or —Si(CH₃)₂—.

[0012] A second aspect of this invention provides a method of modifyinga transparent substrate, comprising:

[0013] applying, in a non-aqueous organic solvent, a silane basedsurface active molecular compound having a reactive silane group at oneend of the molecular compound and a hydrophobic group at the other endof the molecular compound to a surface of a transparent substrate or ona surface of a protective film provided on the transparent substrate.The molecular compound is applied under conditions such that thesilane-based surface active compound is chemically adsorbed on thesurface thereby forming a monomolecule film on the transparentsubstrate. The film comprises a hydrophobic group, an —Si— group whereinthe film is covalently bonded to the applied surface.

[0014] One preferred embodiment of the second aspect of this inventionprovides such a method which comprises:

[0015] contacting a surface of a molded transparent substrate with anorganic solvent solution of a silane-based surface active compoundhaving a reactive silane group at one end of the molecule and ahydrophobic group at the other end of the molecule to form a chemicallyadsorbed monomolecule film of the silane-based surface active compoundon at least one surface of the transparent substrate or over the entiresurface area.

[0016] Another preferred embodiment of the second aspect of thisinvention provides such a method which comprises:

[0017] contacting both of the surfaces of the molded transparentsubstrate with a non-aqueous solvent containing a material having atleast two chlorosilyl groups;

[0018] washing the transparent substrate using a non-aqueous organicsolution to remove any non-reacted material having at least twochlorosilyl groups of the transparent substrate after the contactingstep;

[0019] treating the transparent substrate with water after thenon-reacted material washing step, thereby forming a hydrophilicmonomolecule film composed of a silane material having at least onesilanol group; and

[0020] treating the transparent substrate having the silanol group witha silane-based surface active compound having a reactive silane group atone end of the molecule and a hydrophobic group at the other end of themolecule, thereby laminating a chemically adsorbed hydrophobicmonomolecule film on the hydrophilic monomolecule film having silanolgroups.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic sectional view, enlarged in scale to themolecular level, showing the status of a glass surface in the formationof a chemically adsorbed film;

[0022]FIG. 2 is a schematic sectional view enlarged in scale to themolecular level, showing the status of a glass surface in the formationof a chemically adsorbed film;

[0023]FIG. 3 is a schematic sectional view, enlarged in scale to themolecular level, showing the status of a glass surface in the formationof a chemically adsorbed film;

[0024]FIG. 4 is a schematic sectional view, enlarged in scale to themolecular level, showing the status of a glass surface in the formationof a chemically adsorbed film;

[0025]FIG. 5 is a schematic sectional view, enlarged in scale to themolecular level, showing the status of a glass surface in the formationof a chemically adsorbed film;

[0026]FIG. 6 is a graph showing the surface tension or energy in variouschemically adsorbed films;

[0027]FIG. 7 is a schematic sectional view, enlarged in scale to themolecular level, showing the surface of a windshield glass as anembodiment of the transparent substrate according to the invention;

[0028]FIG. 8 is a schematic sectional view, enlarged in scale to themolecular level, showing the surface of a windshield glass as adifferent embodiment of the transparent substrate according to theinvention;

[0029]FIG. 9 is a schematic sectional view, enlarged in scale to themolecular level, showing a windshield glass as a further embodiment ofthe transparent substrate according to the invention;

[0030]FIG. 10 is a schematic sectional view, enlarged in scale to themolecular level, showing the surface of a windshield glass as a furtherembodiment of the transparent substrate according to the invention; and

[0031]FIG. 11 is a schematic sectional view, enlarged in scale to themolecular level, showing the surface of a windshield glass as a furtherembodiment of the transparent substrate according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The transparent substrate component of the instant invention isusually made of transparent materials such as glass and plastic. Wherethe substrate is made of glass, its surface typically compriseshydrophilic molecules such as hydroxyl groups. Where a plastic is thesubstrate material, the surface may be readily made hydrophilic by anoxidizing treatment. By contacting the substrate material with anon-aqueous organic solvent solution of a compound having a carbon chainand a reactive silane group at one end, a reaction between activehydrogens in the hydrophilic groups of the substrate surface and thereactive silane group forms a monomolecule film. The monomolecule filmis bonded to the surface by an —SiO— group containing chemical bond(i.e., a covalently bonded). Such a reaction is called a chemicaladsorption reaction, and the monomolecule film obtained by this reactionis called a chemically adsorbed single molecule (or unimolecule ormonomolecule) film. In use, when the chemically adsorbed monomoleculefilm is covalently bonded to a real image side mirror surface, itsadhesion is so strong that usually it is not separated unless thesurface of the transparent substrate is cut away. Furthermore, becausethe compound has a hydrophobic group at the other end, the hydrophobicproperties of the monomolecule provides a contamination free effect.

[0033] As noted before, the transparent substrate material may be aplastic material. Suitable plastic materials include acrylic resins andpolycarbonate resins. Such plastic substrates may be used in addition tolo glass, although glass is most extensively used.

[0034] The surface of the transparent substrate has an exposedhydrophilic group. Examples of hydrophilic groups are those groupshaving active hydrogen, e.g., hydroxyl groups, carbonyl groups, aminogroups, imino groups, etc. Where the transparent substrate surface doesnot have a sufficient amount of hydrophilic groups, the surface isrendered hydrophilic by usual means such as electron or ion beamirradiation in an oxygen or nitrogen atmosphere.

[0035] The molecule constituting the chemically adsorbed monomoleculefilm may be a silane-based surface active compound having a chlorosilane(—SiCl_(v)Y_(3−v)) group or an alkoxysilane (Si(OW)_(v)Y_(3−v)) group atone end of the molecule and a hydrocarbon group or fluorine-substitutedcarbon at the other end of the molecule. In the above formulas, vrepresents an integer ranging from 1 to 3, Y represents a hydrogen atomor a lower alkyl (for example C₁ to C₆) or lower alkoxyl group (forexample C₁ to C₆), and W represents a lower alkyl group. Among thesilane-based surface active compounds mentioned above,chlorosilane-based surface active compounds are preferred because theycan reliably undergo a chemical adsorption reaction to form a chemicallyadsorbed monomolecule film at room temperature. Among thechlorosilane-based surface active compounds, those having atrichlorosilane group (v is 3) are preferred because siloxane bondsintervene between adjacent adsorbed molecules. Further, in order toincrease the concentration of the adsorbed molecule, the silane-basedsurface active compound having a straight chain is preferred. Examplesof especially preferred chlolosilane-based surface active compounds arethose represented by the formulas:

R¹—SiCl_(v)Y_(3−v)  (C) and

CF₃—(CF₂)_(t)—(R²)_(r)—SiCl_(v)Y_(3−v)  (D)

[0036] where t is an integer of at least 0, preferably 0 to 10, r is 0or 1, R¹ is an alkyl group of at least 6 (preferably 8 to 22) carbonatoms which may contain a vinyl (CH₂=CH—) or ethynyl (CH≡C—) group ormay be interrupted by a COO group or by a silicon or oxygen atom, R² isan alkylene group of at least one (preferably 1 to 20) carbon atomswhich may contain a vinylene (—CH=CH—), ethynylene (—C=—C—) group or maybe interrupted by a COO group or by a silicon or oxygen atom, and Y is ahydrogen atom, a lower alkyl group (for example C₁ to C₆) or loweralkoxyl group (for example C₁ to C₆), and v is an integer ranging from 0to 2. Preferably, those chlorosilane-based surface active compounds have12 to 22 carbon atoms. More specific examples include:

CH₃(CH₂)₉SiCl₃,

CH₃(CH₂)₁₅SiCl₃,

CH₃CH₂O(CH₂)₁₅SiCl₃,

CH₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,

CF₃(CF₂)₇(CH₂)₂SiCl₃,

CF₃CH₂O(CH₂)₁₅SiCl₃,

CF₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,

CF₃(CF₂)₃(CH₂)₂Si(CH₃)₂(CH₂)₉SiCl₃,

CF₃COO(CH₂)₁₅SiCl₃,

CF₃(CF₂)₅(CH₂)₂SiCl₃.

[0037] Those surface active compounds in which R¹ in the above formulascontains a vinyl or ethynyl group are preferred, because apolymerization of unsaturated bonds with a catalyst, with light or highenergy irradiation, may occur. Polymerization of unsaturated bondsresults in intramolecular bonds and therefore an undesirably firmermonomolecule film.

[0038] Furthermore, the chlorosilane-based surface active compoundshaving a hydrophobic group containing a fluorocarbon group areparticularly preferred, because the resulting monomolecule film ishighly hydrophobic as well as an oil-phobic effect (i.e.,oil-repellant).

[0039] The transparent substrate according to the instant invention isusually manufactured from a molded transparent substrate.

[0040] When the chlorosilane-based surface active material is used, thechemically adsorbed monomolecule film usually has to be washed withoutcontact with water. Water should be avoided because any of the remainingunreacted chlorosilane-based surface active compound reacts with thewater component of the wash and becomes whitish in color.

[0041] Further, the clorosilane-based surface active compound has to bedissolved in a non-aqueous (substantially non-water) organic solventbecause it is highly reactive with water. Examples of applicablesolvents include n-hexadecane, toluene, xylene, dicyclohexyl, carbontetrachioride, chloroform, or freon 113. These solvents may be usedeither alone or in combination. However, it is possible to use methylalcohol or ethyl alcohol as the solvent in cases when other silane-basedsurface active compounds are used rather than those based onchlorosilane.

[0042] To form the chemically adsorbed monomolecule film according tothe invention, one surface of the transparent substrate may be contactedwith a material having at least two chlorosilyl groups, before asilane-based surface active compound containing a hydrophobic group ischemically adsorbed on the transparent substrate surface. The materialhaving at least two Cl—Si groups reacts with an activehydrogen-containing group of the transparent substrate surface, reactingone or more Cl—Si groups but not all of them, so the unreacted Cl—Sigroups remain in the reacted material. The surface of the transparentsubstrate thus-treated is then washed with an organic solution to removethe unreacted material containing at least two chlorosilyl groups. Thesurface is then treated with water (washing with water or exposing toair to react with moisture in the air) to form a monomolecule filmcontaining silanol groups (Si—OH) on the surface of the substrate (seeFIG. 9).

[0043] Formation of a monomolecule film containing silanol groups isdesirable because a silane-based surface active compound can bechemically adsorbed at a high concentration even when the substrate hasonly a very small quantity of hydrophilic groups, such as a quartz glassor tempered glass. Examples of materials having at least two chlosilylgroups are:

SiCl₄, SiHC1₃, SiH₂Cl₂,

Cl—(SiCl₂O)_(i)SiCl₃, and

H_(l)(R³)_(3−l)Si(R⁴)_(i)SiCl_(k)(R⁵)_(3−k).

[0044] It is usually desired that the number of Cl—Si bonds is as largeas possible for high concentration chemical adsorption of thesilane-based surface active compound containing hydrophobic groups. Inthe above formulas, i represents an integer such as 1 to 4, 1 and k eachrepresent an integer ranging from 1 to 3, R³ and R⁵ are lower-alkylgroups, and R⁴ represents an alkylene group with a carbon number of atleast 1 such as 1 to 6. Preferably the materials have 3 or 4 Cl—Si bondsand are inorganic. Therefore, SiCl₄ is most preferred as the materialcontaining a chlorosilyl group, because it is a very small molecule andis highly reactive for producing silanol groups. Thus it is highlyeffective for making a quartz glass surface uniformly hydrophilic.

[0045] It is possible to form a chemically adsorbed mono-molecule filmcontaining a hydrophobic group on only one surface of a transparentsubstrate and form a chemically adsorbed monomolecule film containing ahydrophilic group on the other surface, thus obtaining a substrate withhas different characteristics on opposite sides. Such a substrate may beobtained by chemically adsorbing the above-mentioned material containinga chlorosilane group on both surfaces of a transparent substrate. Bothsurfaces are then treated as described above to form silanol groups. Thesurface on which it is desired to leave a hydrophilic monomolecule filmis then coated with an aqueous solution of a water-soluble polymermaterial, e.g., polyvinyl alcohol or prulane. A chemically adsorbedmonomolecule film containing a hydrophobic group is then formed on theother surface of the substrate. Subsequently the water-soluble polymermaterial is washed away with water.

[0046] The chemically adsorbed monomolecule film according to theinvention may be either a single monomolecule layer or a lamination oftwo or more monomolecule layers. In the latter case, however, it isnecessary to form chemical bonds between adjacent laminated layers. Forproducing such a lamination of monomolecule layers, one preferred methodis as follows. First a chlorosilane based surface active compound (forexample, of the formula (C) mentioned above) having a group (such as avinyl or ethynyl group) that can subsequently be converted to an activehydrogen-containing reactive group (such as a hydroxyl, imino or aminogroup) is used to form a monomolecule film. The convertible group isthen converted to the active hydrogen-containing reactive group. Achlorosilane-based surface active compound is applied to this treatedsurface to form a hydrophobic monomolecule film.

[0047] The chemically adsorbed monomolecule film formed on the substratesurface is as thin as of the order of the nanometer (nm) and does notspoil the intrinsic transparency of the substrate. In addition, thechemically adsorbed monomolecule film according to the invention hashydrophobic properties and is therefore not readily susceptible tosurface contamination. Further, by forming a chemically adsorbedhydrophobic monomolecule film on one surface of a transparent substrateand forming a chemically adsorbed hydrophilic monomolecule film on theother surface of the substrate, a transparent substrate which hashydrophobic and contamination-free effects on one surface and anantifogging effect on the other surface can be obtained.

[0048] This invention can be applied to a variety of materials includinga display-form touch panel switch, a face plate for photocopy machine, afresnel plate for an overhead projector, a display glass, a displayoptical filter, a halogen lamp, a mercury lamp a sodium lamp, anelectric bulb, a chandelier, a glass or plastic lens, a microscope lensa telescope lens, a binocular lens, a magnifying glass lens and otherapparatus lenses.

[0049] This invention will now be illustrated with reference to thefollowing examples and the drawings, but the scope of the invention isnot to be construed as limited to these examples.

EXAMPLE 1

[0050] In a chloroform solution containing 80 wt % n-hexadecane and 12wt % carbon tetrachloride a silane-based surface active compoundrepresented by a formula:

CH₂=CH—(CH₂)₁₆—SiCl₃

[0051] containing vinyl groups (CH₂=CH—)₂ (see FIG. 1) is dissolved to aconcentration of 3×10⁻³ to 5×10⁻² Mol. A glass substrate 1 as atransparent substrate was dipped into the solution and held at roomtemperature for one hour. The surface of the glass substrate 1 containeda number of hydroxyl groups and a reaction took place between thechlorosilyl groups (—SiCl) in the chlorosilane-based surface activecompound and the hydroxyl groups (—OH) and a bond represented such asformula 1:

[0052] is formed on the substrate surface.

[0053] The glass substrate 1 was then washed with freon 113 to removethe material remaining on the surface without any reaction, followed bywashing the surface with water or exposing the surface to air to reactwith moisture in the air. The —SiCl group was changed to a —SiOH groupas in formula 2.

[0054] Each silanol group (—SiOH) was then dehydrated and crosslinked toform a siloxan bond (—Si O—) as in formula 3.

[0055] Thus, an adsorbed monomolecule protective film 3 containing avinyl group 2 was formed as a single layer with a thickness from about 2to 3 nm on the surface in a chemically coupled form via oxygen atoms(see FIG. 1). The glass substrate is then irradiated in an atmospherecontaining oxygen or N₂ (or in air) with about 3 Mrads of an energy beam(e.g., electron beam, X-rays, gamma (γ) rays, ultraviolet (UV) rays orion beam), thus providing the vinyl group portion 2 with a hydroxyl(—OH) groups 4 (in case of oxygen atmosphere) as shown in FIG. 2 oramino (—NH₂) group 5 (in case of nitrogen atmosphere) as shown in FIG.3. The hydroxyl, amino, and/or imino groups may be formed in air.

[0056] The fact that these functional groups are attached to vinylgroups is confirmed from FT-IR analysis.

[0057] It is possible to process the vinyl groups arranged on thesurface in plasma containing O₂ or N₂ as well to form an adsorbedmonomolecule protective film 3-1 (see FIG. 4) with attached —OH groupsas shown in FIG. 2 or an adsorbed monomolecule protective film 3-2 withattached —NH₂ groups as shown in FIG. 3.

[0058] Finally, a solution of a mixed solvent composed of 80 wt %n-hexane, 12 wt % carbon tetrachloride and 8 wt % chloroform wasprepared by dissolving a silane-based surface active compound containingfluorine represented by a formula:

F(CF₂)_(m)(CH₂)_(n)SiR_(q)X_(3−q)  (A)

[0059] where m represents an integer ranging from 1 to 15, n representsan integer ranging from 0 to 15, the sum of m and n ranges from 10 to30, q represents an integer ranging from 0 to 2, R represents an alkylor an alkoxyl group, and X is a halogen atom or an alkoxyl group; or

F(CF₂)_(m′)(CH₂)_(n′)A(CH₂)_(p)SiR_(q)X_(3−q)  (B)

[0060] where m′ represents an integer ranging from 1 to 8, n′ representsan integer ranging from 0 to 2, p represents an integer ranging from 5to 25, q represents an integer ranging from 0 to 2, X represents ahalogen atom or an alkoxyl group, R represents an alkyl or an alkoxylgroup, and A represents —O—, a —COO— or —Si(CH₃)₂ , for instance:

CF₃CH₂O(CH₂)₁₅SiCl₃

[0061] in a concentration of the order of 2×10⁻³ to 5×10⁻² Mol. Theglass substrate with the adsorbed monomolecule protective film 3-1 or3-2 formed thereon was dipped in to the solution and held therein forone hour. The —OH group, —NH group or —NH₂ group were exposed on thesubstrate surface as shown in FIG. 2 or 3, a reaction was brought aboutbetween the chlorosilyl group of the chlorosilane-based surface activecompound containing fluorine and the —OH, —NH or —NH₂ groups. Thuscovalent bonds were formed on the surface, represented as the followingformula 4.

[0062] This reaction proceeds substantially the same as above informulas 1 to 3.

[0063] Thus, a highly concentrated monomolecule film lamination 7 isformed on the surface of the glass substrate such that an adsorbedmonomolecule film 6 containing fluorine is chemically bonded to a loweris adsorbed monomolecule film 3-1 as shown in FIG. 4 or to a loweradsorbed monomolecule film 3-2 as shown in FIG. 5.

[0064] Where no monomolecule film is required between a hydrophobicoil-phobic surface film and a glass substrate, a chlorosilane-basedsurface active compound may be used to form an adsorbed monomoleculeprotective film. By so doing, a single layer of adsorbed monomoleculeprotective film containing fluorine on the surface can be formed.

[0065] Where a plurality of monomolecule films are necessary asprotective films, CH₂=CH—(CH₂)_(n)SiCl₃ may be used as a chemicaladsorption reagent. The steps of chemical adsorption and radiationirradiation may be repeated, and finally a chlorosilane-based surfaceactive compound containing fluorine may be adsorbed as a chemicalreagent. Thus, a hydrophobic oil-phobic film comprising a single layerof an adsorbed monomolecule film containing fluorine may be formed onthe surface via a plurality of necessary protective films.

[0066] In the above embodiment, CF₃CH₂O(CH₂)₁₅SiCl₃, was used as asilane-based surface active compound containing fluorine outer mostsurface. However, it is possible to use other compounds as well, forinstance;

CF₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,

CF₃(CF₂)₃(CH₂)₂Si(CH₃)₂(CH2)₉SiCl₃,

CF₃COO(CH₂)₁₅SiCl₃, and

CF₃(CF₂)₇(CH₂)₂SiCl₃.

[0067] The surface energy or tension in the adsorbed monomolecule filmwas measured by evaluation of the water dip angle of contact (with anautomatic contact angle gauge manufactured by Kyowa Kaimen Kagaku Co.).The results are shown in FIG. 6. FIG. 6 is a graph showing relationsbetween cos θ and surface tension.

[0068] As is seen from FIG. 6, the surface energy is reduced as thenumber of fluorine atom increases. It is confirmed that when the numberof fluorine atoms is 9 or more, the surface tension of the film is lowerthan that of polytetrafluoroethylene and that the surface is very highlyhydrophobic and oil-phobic.

[0069] The water wetting angle measured at the surfaces of the adsorbedfilm was found to be about 140 to 150 degrees.

[0070] Thus, by using such glasses, it is possible to provide awiperless motor vehicle windshield or windscreen glasses andsimultaneously prevent fogging of the glass lens surface.

[0071] In FIG. 6, F17, F9, F3 and NTS designate adsorbed monomolecularfilms respectively of;

CF₃(CF₂)₇(CH₂)₂—Si(CH₃)₂(CH₂)₉SiCl₃,  F17;

CF₃(CF₂)₃(CH₂)₂O(CH₂)₁₅SiCl₃,  F9;

CF₃COO(CH₂)₁₅SiCl₃, and  F3;

CH₃(CH₂)₁₉SiCl₃  NTS;

[0072] The above embodiment is directed to tempered glass. However, theinstant invention is applicable to all the glasses where improvement ofthe quality of the glass surfaces is a goal. For example, the abovedescribed embodiment finds particular use as a film for window glassesin vehicles, electric cars, aircraft and other means of transport, aswell as mirrors, glass vessels, glass or plastic lenses and other glassor plastic surfaces wherein hydrophobic and oil-phobic characteristicsare required.

[0073] Further, while the above embodiment is concerned with theadsorbed monomolecule films as glass protective films, the transparentsubstrate according to the invention is by no means limited to glass,but it may of course be protective films having functions aslight-blocking films, ultraviolet absorption films and infraredabsorption films as well.

[0074] Further, the glass is not limited to colorless transparent glass,but the invention is applicable to roughened surfaces and also tocolored glass and glass fibers.

[0075] In general, the invention is applicable to all techniques ofchemical coupling of glass or plastic having hydrophilic groups on thesurface and a silane-based surface active compound containing afluorophobic by using a chemical adsorption process.

[0076] Where the surface of the protective film or transparent substrateitself is not hydrophilic, the silane-based surface active compoundcontaining a hydrophobic group may be provided after making the surfacehydrophilic by usual methods, such as corona discharge in an atmospherecontaining oxygen or alternatively by spattering.

[0077] The chlorosilane-based surface active compounds, in one preferredembodiment, are represented by the formulae

F(CF₂)_(m)(CH₂)_(n)SiR_(q)X_(3−q) or

F(CF₂)_(m′)(CH₂)_(n′)A(CH₂)pSiR_(q)X³⁻q

[0078] When one of these compounds is employed, a highly concentratedand very thin organic film can be formed. The film is substantially pinhole free, with a uniform thickness, thereby forming a hydrophobicoil-phobic monomolecule film chemically coupled to the glass substratesurface. The symbols in the above formulas (A) and (B) are as definedhereinbefore.

[0079] It is thus possible to effect a very highly durable surfacetreatment for prevention of contamination, fogging and wetting of theglass surface.

EXAMPLE 2

[0080] A transparent substrate, shaped for use as a motor vehiclewindshield or windscreen glass, was washed with an organic solution.Simultaneously a material containing a fluorocarbon group and achlorosilane group having the formula:

CF₃(CF₂)₇(CH₂)₂SiCl₃

[0081] was dissolved in a non-aqueous solvent, i.e., a mixed solventcomposed of 80 wt % of n-hexadecane, 12 wt % of carbon tetrachloride and2-8 wt % of chloroform. The windshield glass was dipped into thesolution and immersed for about 2 hours. The windshield glass hadnumerous hydroxyl groups on the surface, and thus a dehydrochlorinationreaction was brought about between the chlorine in chlorosilyl (—SiCl)group of the material containing a fluorocarbon group and a chlorosilanegroup and a hydroxyl group and covalent bonds represented by formula 5below were formed over the entire surface of the windshield glass. Thisreaction proceeded substantially the same as described above in formulas1 to 3.

[0082] Thus, a single layer of chemically adsorbed monomolecule film 12containing fluorine was formed in a state chemically coupled to thewindshield glass 11 by siloxane bonds, as shown in FIG. 7. The thicknessof this chemically adsorbed monomolecule film was assumed from themolecular structure to be about 1.5 nm. The monomolecule film waschemically coupled very firmly.

[0083] The treated windshield glass was then tested to compare theproperties of treated windshield glass with untreated windshield glass.The treated windshield glass had greatly reduced contamination comparedto windshield glass without the above-described treatment. Contaminants,if attached, could be easily removed by merely rubbing the glass with abrush or the like. Doing so produced neither scars nor scratches on thesurface of the windshield glass 11. Further, it was possible to removeoily contaminants by merely washing with water.

[0084] Where plastic materials such as polyacrylic resins and lopolycarbonate resins were used as the material of the transparentsubstrate, the techniques described above could be used to oxidize thesurface. Subsequently, the oxidized surface could then be treated withwater or air, as also described above, to make the surface hydrophilic.In particular, this means plasma treatment of the surface at 300 W forabout 10 minutes to make the surface oxidized and hydrophilic whilereplacing the adsorption liquid with a freon 113.

EXAMPLE 3

[0085] A solution was developed by dissolving about 1 wt. % of SiCl₄ asa material containing chlorosilyl groups in a chloroform solvent as anon-aqueous solvent. A windshield glass with the surface containing lesshydroxyl groups (although hydrophilic, e.g., an annealedly temperedglass) was dipped into the solution and immersed for about 30 minutes.Then a dehydrochlorinizing reaction was brought about on the surface ofthe windshield glass 21 due to the presence of some hydroxyl (—OH)groups 2 as hydrophilic groups on the surface, as shown in FIG. 8. Achlorosilane monomolecule film constituted by a material containingchlorosilyl groups was formed. By using SiCl₄ as a material containingchlorosilyl groups, a dehydrochlorination reaction was brought about onthe surface of the windshield glass 21 even in the presence of only asmall amount of hydrophilic OH groups 22 on the surface of the frontwindow glass 21. Furthermore, molecules such as formula 6 and 7 aresecured to the surface via —SiO— bonds.

[0086] In this case, non-reacted SiCl₄ may also be present on thechlorosilane monomolecule film. However, by subsequently washing thesurface of the windshield glass 21 with chloroform as a non-aqueoussolvent and then with water, the hydroxyl groups and non-reacted SiCl₄molecules on the surface can be removed to obtain on the surface asiloxane monomolecule film 23. The film is represented as formula 8 and9 as shown in FIG. 5.

[0087] The monomolecule film 23 formed in this case is completelycoupled to the surface of the windshield glass 21 via chemical bonds of—SiO—, and therefore it is never separated from the surface. Inaddition, the siloxane monomolecule film 23 thus obtained has numeroussurface —SiOH bonds, the amount of which roughly corresponds to aboutthree times the number of the initial hydroxyl groups.

[0088] In the solution mentioned before in connection with Example 2,the windshield glass was dipped in to the solution and immersed forabout one hour. Thereupon, the windshield glass 21 developed thesiloxane monomolecule film 23 on its surface. As a result, bonds asshown such as above in formula 5 were formed on the surface of thesiloxane monomolecule film 23.

[0089] Thus, a chemically adsorbed monomolecule film 24 containingfluorine was formed to a thickness of about 1.5 nm. over the entireglass surface in a state chemically coupled to the lower siloxanemonomolecule film 23, as shown in FIG. 10. A separation test showed thatthe monomolecule films are never separated.

[0090] The windshield glass of this example was tested under real useconditions. The results indicate that no water drops were attached dueto the hydrophobic effect of the surface fluorine. Acetone containingwax was blown against the glass by assuming the flow of wax component.It was found that oil was repelled and no fogging was produced due tothe effect of the oil-phobic properties of fluorine in the monomoleculefilm chemically adsorbed to the surface. In addition, contaminants thatwere attached could be easily wiped away.

EXAMPLE 4

[0091] A transparent substrate, a display-form touch panel glass (switchof CRT glass), was prepared and washed with an organic solvent.Simultaneously,, a material containing carbon fluoride groups andchlorosilane groups, namely

CF₃(CF₂)₇(CH₂)₂SiCl₃

[0092] was dissolved to a concentration of 1 wt. % in a non-aqueoussolvent, i.e., a mixed solvent containing 80 wt. % of n-hexadecane, 12wt. % of carbon tetrachloride and 8 wt. % of chloroform. The CRT glasswas dipped into the solution and immersed for about 2 hours. The CRTglass had numerous hydroxyl groups on the surface, and thus adehydrochlorination reaction was brought about between the chlorine in—SiCl groups of the material containing carbon fluoride groups andchlorosilane groups and hydroxyl groups on the surface. This reactionproduced bonds represented by above formula 5 below over the entiresurface of the CRT glass. This reaction proceed substantially the sameas above in formulas 1 to 3.

[0093] Thus, a single layer of chemically adsorbed monomolecule filmcontaining fluorine was formed and chemically coupled (i.e., covalentlybonded) to the CRT glass by siloxane bonds. The thickness of thischemically adsorbed monomolecule film was about 1.5 nm. The monomoleculefilm was chemically coupled very firmly and was never separated.

[0094] The resultant CRT glass was tested under actual use conditions.Its contamination affinity was found to be greatly reduced compared toCRT glass without treatment. Contaminants, if attached, could be easilyremoved by merely wiping the glass with a paper or the like. Doing soproduced neither scars nor scratches on the surface of the CRT glass.

EXAMPLE 5

[0095] This example is directed to a fresnel plate glass for an overheadprojector wherein the surface contains less hydroxyl groups, althoughstill hydrophilic in nature, e.g., an annealedly tempered glass. Theglass was treated by immersing the glass for about 30 minutes in asolution. The immersion solution was developed by dissolving about 1 wt.% of SiCl₄ as a material containing chlorosilyl groups in a chloroformsolvent (a non-aqueous solvent). The immersion initiated a chemicaldehydrochlorinizing reaction on the surface of the fresnel plate glassdue to the presence of some hydroxyl (—OH) groups as hydrophilic groups(inner layer film) on the surface. As the inner layer film formingmaterial, other materials could be used in place of SiCl₄ such asSiHC1₃, SiH₂Cl₂, Cl—(SiCl₂ O)n SiCl₃ (n being integer).

[0096] A chlorosilane monomolecule film (inner layer) constituted by amaterial containing chlorosilyl groups was formed on the glass. By usingSiCl₄ as a material containing chlorosilyl groups, a dehydrochlorinationreaction was brought about on the surface of the fresnel plate glasseven in a presence of only a small amount of hydrophilic OH groups onthe surface of the fresnel plate glass. Furthermore, molecules describedabove by formulas 6 and 7 were secured to the surface via —SiO— bonds.

[0097] In this case, non-reacted SiCl₄ is also present on thechlorosilane monomolecule film. By subsequently washing the surface ofthe fresnel plate glass with chloroform (as a non-aqueous solution) andthen washing with water, the hydroxyl groups and non-reacted SiCl₄molecules on the surface can be removed. The removal of the hydroxylgroups and non-reacted SiCl₄ results in a siloxane monomolecule filmrepresented such as above formulas 8 and 9 on the surface.

[0098] Further, as a material containing carbon fluoride groups andchlorosilane groups;

CF₃(CF₂ )₇(CH₂)₂SiCl₃

[0099] was dissolved to a concentration of 2 wt. % in a non-aqueoussolvent, i.e., a mixed solvent containing 80 wt. % of n-hexadecane, 12wt. % of carbon tetrachloride and 8 wt. % of chloroform. The glass wasimmersed into the solution for about 1 hour. The glass had numeroushydroxyl groups on the surface, and thus a dehydrochlorination reactionwas brought about between (1) the chlorine in the —SiCl groups of thematerial containing carbon fluoride groups and chlorosilane groups and(2) hydroxyl groups. The reaction produced bonds represented by aboveformula 5 over the entire surface of the glass.

[0100] Thus, the chemically adsorbed monomolecule film containingfluorine was formed in a state chemically coupled to the glass bysiloxane bonds. The thickness of this chemically adsorbed monomoleculefilm was assumed from the molecular structure to be about 1.5 nm. Themonomolecule film was chemically coupled very firmly and was neverseparated.

[0101] When chemically adsorbing a monomolecule film using a non-aqueoussolvent incorporating carbon fluoride groups and chlorosilane groups, anaqueous solution containing polyvinyl alcohol was also coated as ahydrophilic film. The hydrophilic film has resistance against an organicsolvent on the surface which was desired to be left hydrophilic (inorder to impart an antifogging effect). After the adsorption was over,the hydrophilic film was washed with water, thus obtaining a windshieldglass with a hydrophobic, oil-phobic contamination free monomoleculefilm 24 formed on one surface and a monomolecule film 23 containinghydrophilic hydroxyl groups on the other surface, as shown in FIG. 11.The antifogging effect of this glass was tested under simulated actualuse conditions, and it was found that the glass surface left hydrophilicwas never fogged.

[0102] In Example 2, only a single layer of monomolecule film wasformed, and in Example 3 only a single layer of silane-based surfaceactive compound containing fluorine was formed after formation of asingle layer of siloxane monomolecule film. However, the same effectscan be obtained by laminating a plurality of chemically adsorbedmonomolecule films according to the invention instead of forming only asingle layer.

[0103] Further, while the above example used CF₃(CF₂ )₇(CH₂)₂SiCl₃ byadding or incorporating vinylene (—CH=CH—) or ethynylene (—C≡C—) groupsto or in portion represented as R in chlorosilane-based surface activecompound represented as CF₃(CF₂)_(t)—(R²)y—SiCl_(v)X_(3−V), (wherein thesymbols are as defined before) crosslinking can be obtained with about 5Mrads of electron beam radiation after the formation of the monomoleculefilm for further improvement of the hardness of the monomolecule film.

[0104] Alternative compounds could be used in addition to or in place ofthe above described trichlorosilane-based surface active compounds. Forexample:

CF₃CH₂O(CH₂)₁₅SiCl₃,

CF₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,

CF₃(CF₂)₃(CH₂)₂Si(CH₃)₂(CH₂)₉SiCl₃,

CF₃COO(CH₂)₁₅SiCl₃,

CF₃(CF₂)₇(CH₂)₂SiCl₃,

CF₃(CF₂)₅(CH₂)₂SiCl₃,

[0105] and chlorosilane-based surface active compounds such as;

CF₃CH₂O(CH₂)₁₅Si(CH₃)₂C1,

CF₃(CH₂)₂Si(CH₃)₂C1,

CF₃CH₂O(CH₂)₁₅Si(CH₃)C1₂,

CF₃COO(CH₂)₁₅Si(CH₃)₂C1,

[0106] and chlorosilane-based surface active compounds of containingmethoxy group such as;

CF₃CH₂O(CH₂)₁₅Si(OCH₃)₂C1,

CF₃(CH₂)₂Si(OCH₃)₂C1,

CF₃CH₂O(CH₂)₁₅Si(OCH₃)C1₂, and

CF₃COO(CH₂)₁₅Si(OCH₃)₂C1.

[0107] Similar effects could be obtained with such alkoxysilane-basedsurface active compounds such as CF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃, and CF₃CH₂O(CH₂)₁₅Si(OCH₃)₃ by heating the surface active compound solution.Further, with chlorosilane-based surface active compounds havinghydrocarbon groups such as;

CH₃(CH₂)₉SiCl₃,

CH₃(CH₂)₁₅SiCl₃,

CH₃CH₂O(CH₂)₁₅SiCl₃, and

CH₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,

[0108] can be chemically adsorbed as a monomolecule film. Thesecompounds were similarly formed into a monomolecule at room temperatureto obtain the hydrophobic and contamination free effects describedabove.

[0109] As has been described in the foregoing, according to the instantinvention a very thin transparent hydrophobic monomolecule film isformed on the transparent glass surface, and therefore the gloss whichis intrinsic to the transparent glass is not spoiled. Further, thehydrophobic monomolecule film is highly hydrophobic and oil-phobic andthus enhances the repellency to contamination characteristics of thesurface. It is therefore possible to provide a highly contaminationfree, high performance transparent glass. Further, an antifogging effectcould be obtained by leaving part of the substrate surface hydrophilic

[0110] According to the invention, by using a chemical adsorptionmethod, a hydrophobic monomolecule film with a small thickness (of thenanometer level) can be formed on the surface of a transparent substratewithout spoiling gloss and transparency thereof. If the hydrophobicmonomolecule film contains a fluorocarbon group, it has excellenthydrophobic and oil-phobic properties and permits improvement of surfacecontamination prevention effect. It is also possible to form achemically adsorbed monomolecule film having hydrophobic andcontamination prevention properties on one surface and a chemicallyadsorbed monomolecule film containing hydrophilic groups on the othersurface. This treatment thus provides a transparent substrate havingdifferent natures on opposite sides.

[0111] It is therefore possible to provide a transparent substrate,which is highly antifogging, hydrophobic, oil-phobic and contaminationfree.

[0112] While the above invention has been disclosed with respect tospecific embodiments thereof, it is not limited thereto. The subjoinedclaims are intended to be construed to encompass the present inventionin its full spirit and scope including such other variants andmodifications as may be made by those skilled in the art withoutdeparting from that true spirit and scope.

What is claimed:
 1. A transparent substrate comprising at least onemonomolecule film formed as an outer most surface layer on at least onesurface of the transparent substrate either directly or indirectly,wherein the monomolecule film contains a hydrophobic group and is bondedthrough a covalent bond to the surface of the substrate.
 2. Thetransparent substrate according to claim 1 , wherein the monomoleculefilm containing hydrophobic groups is bonded to the surface through a—Si— group.
 3. The transparent substrate according to claim 1 , whereinthe monomolecule film containing hydrophobic group is bonded to thesurface through siloxane bonds via a siloxane-based protective filmprepared on the substrate.
 4. The transparent substrate according toclaim 1 , wherein the hydrophobic group is a fluorine-containinghydrocarbon group.
 5. A transparent substrate comprising a monomoleculefilm formed as an outer most surface layer on both surfaces of thetransparent substrate either directly or indirectly, wherein one of thesurfaces is covered with a covalently bonded monomolecule filmcontaining a hydrophobic group, and the other surface is covered with acovalently bonded monomolecule film containing a hydrophilic group. 6.The transparent substrate according to claim 5 , wherein the hydrophobicgroup is a fluorine-containing hydrocarbon group.
 7. The transparentsubstrate according to claim 5 , wherein the hydrophilic groups is ahydroxyl group.
 8. A transparent substrate comprising at least onemonomolecule film formed as an outer most surface layer on at least onesurface of the transparent substrate either directly or via a protectivefilm, wherein the monomolecule film is formed by a chemical covalentbonding from a silane halide-based or alkoxy silane-based surface activecompound of the formula: F′(CF₂)m(CH₂)nSiRqX_(3−q)  (A) where mrepresents an integer ranging from 1 to 15, n represents an integerranging from 0 to 15, the sum of m and n ranges from 10 to 30, qrepresents an integer ranging from 0 to 2, R represents an alkyl or analkoxyl group, and X is a halogen atom or an alkoxyl group, or of theformula: F(CF₂)m′(CH₂)n′A(CH₂)pSiRqX_(3−q)  (B) [where m′ represents aninteger ranging from 1 to 8, n′ represents an integer ranging from 0 to25, q represents an integer ranging from 5 to 25, q represents aninteger ranging from 0 to 2, X represents a halogen atom or an alkoxylgroup, R represents an alkyl or an alkoxyl group, and A represents —O—,a —COO— or —Si(CH₃)₂—].
 9. The transparent substrate according to claim8 , wherein the monomolecule film is bonded to the protective filmcovering the substrate through a chemical covalent bond.
 10. Thetransparent substrate according to claim 8 , wherein said silanehalide-based surface active compound is a chlorosilane-based surfaceactive compound of the formula:CF₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,CF₃(CF₂)₃(CH₂)₂Si(CH₃)₂(CH₂)₉SiO1₃,CF₃CH₂O(CH₂)15SiCl₃,CF₃COO(CH₂)15SiCl₃,CF₃(CF₂)₇(CH₂)₂Si(OCH₃)C1₂,orCF₃(CF₂)₇(CH₂)₂Si(CH₃)C1₂.
 11. A method of modifying a surface of atransparent substrate comprising: applying, in a non-aqueous organicsolvent, a silane-based surface active compound having a reactive silanegroup at one end and a hydrophobic group at the other end containingfluorine, to a surface of the transparent substrate or on a surface of aprotective film provided on the transparent substrate under suchconditions that the silane-based surface active compound is chemicallyadsorbed to the surface, thereby forming a monomolecule film having thehydrophobic group and —Si— group and being covalently bonded to theapplied surface.
 12. The method of according to claim 11 , wherein thesilane-based surface active compound is a chemical material containingan end chlorosilyl (—SiCl) group.
 13. A method of modifying a surface ofa transparent substrate comprising: contacting a surface of a moldedtransparent substrate with an organic solvent solution of a silane-basedsurface active compound having a reactive silane group at one end and ahydrophobic group at the other end to form a chemically adsorbedmonomolecule film from the silane-based surface active compound on atleast one surface of the transparent substrate or over the entiresurface area
 14. The method according to claim 13 , wherein the reactivesilane group is a chlorosilane group.
 15. The method according to claim13 , wherein the silane-based surface active compound is represented bythe formula: CF₃—(CF₂)_(t)—(R²)_(r)—SC1_(V)Y_(3−v) [where t is aninteger of at least 0, preferably 0 to 10, is 0 or 1, R² is an alkylenegroup of from 1 to 20 carbon atoms which may contain a vinylene(—CH=CH—), ethynylene (—C≡—C—) group or may be interrupted by a —O—,—Si(CH₃)₂— or —COO—, Y is a hydrogen atom, a lower alkyl group or loweralkoxyl group and v is an integer ranging from 0 to
 2. 16. A transparentmethod of modifying a surface of a molded substrate having two surface,comprising: (A) contacting both of the surface of the molded transparentsubstrate with a non-aqueous solvent containing a material having atleast two chlorosilyl groups; (B) washing the transparent substrateusing a non-aqueous organic solution to remove the non-reacted materialhaving at least two chlorosilyl groups of the transparent substrateafter the contacting step; (C) treating the transparent substrate withwater after the non-reacted material washing step, thereby forming ahydrophilic monomolecule film composed of a silane material having atleast one silanol group; and (D) treating the transparent substratehaving thus formed silanol groups with silane-based surface activecompound having a reactive silane group at one end and a hydrophobicgroup at the other end, thereby laminating a chemically adsorbedhydrophobic monomolecule film on the hydrophilic monomolecule filmhaving silanol groups.
 17. The method according to claim 16 , whichfurther comprises between the steps (C) and (D), coating one surface ofthe transparent substrate with a water-soluble coating film and, afterthe step (D), removing the water soluble coating film, thereby forming ahydrophobic monomolecule film on one surface and a hydrophilicmonomolecule film on the other surface.
 18. The method according toclaim 16 , wherein the reactive silane group is a chlorosilane group.19. The method according to claim 16 , wherein the silane-based surfaceactive compound is represented by the formula:CF₃—(CF₂)_(t)—(R²)r—SiCl_(v)Y_(3−v) where t is an integer of at least 0,preferably 0 to 10, r is 0 or 1, R is an alkylene group of from 1 to 20carbon atoms which may contain a vinylene (—CH=CH—), ethynylene (—C≡—C—)group or may be interrupted by a —O—, —Si(CH₃ )₂— or —COO—, Y is ahydrogen atom, a lower alkyl group or lower alkoxyl group and v is aninteger ranging from 0 to
 2. 20. The method according to claim 16 ,wherein the material having at least two chlorosilyl groups is selectedfrom the group consisting of: SiCl₄,SiHC1₃,SiH₂C1₂,andC1—(SiCl₂O)_(n)SiCl₃ (where n is an integer of 1 to 4)
 21. Atransparent substrate comprising at least one monomolecule film formedas an outer most surface layer on at least one surface of an opticaldevice, either directly or indirectly, wherein said monomolecule filmcontains a hydrophobic group and is bonded through a covalent bond tothe surface of said optical device, wherein said optical device isselected from the group consisting of motor vehicle glasses andwindshields, building window glasses, mirrors, optical lenses, fresnellenses, glass lenses, and transparent tempered glass.
 22. Thetransparent substrate as recited in claim 21 , wherein said opticaldevice is a vehicle windshield.
 23. The transparent substrate as recitedin claim 21 , wherein the outer surface of said substrate issufficiently hydrophobic to render said substrate non-adherent to oiland water.
 24. The transparent substrate as recited in claim 21 ,wherein said monomolecule film comprises a chlorosilane molecule havinga fluoroalkyl group, wherein the number of fluorine atoms counted fromthe end of the molecule is between 9 and
 31. 25. The transparentsubstrate as recited in claim 21 , wherein said monomolecule filmcomprises a chlorosilane selected from the group consisting ofCH₃(CH₂)₉SiCl₃, CH₃(CH₂)₁₅SiCl₃, CH₃CH₂ O(CH₂)₁₅SiCl₃, andCH₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃.
 26. The transparent substrate as recitedin claim 24 , wherein said chlorosilane is selected from the groupconsisting of CF₃(CF₂)₇(CH₂)₂SiCl₃, CF₃(CF₂)₇(CH₂)₂SiCl3,CF₃CH₂O(CH₂)₁₅SiCl₃, CF₃(CH₂)₂Si(CH₃)₂(CH₂)₁₅SiCl₃,CF₃(CF₂)₃(CH₂)₂Si(CH₃)₂(CH₂)₉SiCl₃, CF₃COO(CH₂)₁₅SiCl₃,CF₃(CF₂)₅(CH₂)₂SiCl₃.